C-55 Juan de la Barrera

The C-55 lies on white sand about 22 to 25 m down off Cancún, the hull of a Mexican Navy gunboat that began as the American minesweeper USS Ransom. The stern is reported to rest on its left side, and with bare sand all round, barracuda, groupers and snappers gather around the wreckage while lobsters and eels shelter in it.

The hull is no longer in one piece. It is reported to have broken into four sections when Hurricane Wilma struck in 2005, with only a little penetration left on the back deck and the rest in pieces. Treat any opening as an overhead space.

Advanced Open Water is the level to plan on, because of the depth and the current. The boat takes about 40 minutes from the Cancún dock, in small drift groups, and the operator arranges the park wristband and the accredited guide the national park requires.

The hull on the sand began life as USS Ransom, an American Admirable-class minesweeper launched in California in 1943. She came through the Pacific war and ended up as a Mexican Navy gunboat. Off Okinawa on 6 April 1945 she is credited with shooting down three suicide aircraft while rescuing 52 survivors of the destroyers Rodman and Emmons.

Ransom was launched on 18 September 1943 and commissioned in August 1944. After the war she swept mines off Nagasaki, clearing 73 in a month, and earned three battle stars. Recommissioned in 1951 during the Korean War, she did not serve in the war zone.

Mexico bought her in 1962 as ARM DM-12. She was renamed ARM Teniente Juan de la Barrera (C-55) in 1994, and on 25 October 2000 the Navy sank her as an artificial reef 1.

The wreck zone has strong to moderate currents and is not recommended for beginner divers 1. Descend and ascend on a line and carry a surface marker buoy.

Some operators sell the C-55 and C-58 as one morning and others choose the wreck on the day, so ask which hull is on the plan.

If a guide offers penetration, treat it as an overhead dive: the hull is reported broken into sections. Without wreck and overhead training, stay outside the openings. Both wrecks share one published position, so a map pin is only approximate and the boat crew is the reliable guide to the hull.